On Monday evening, just 12 hours before the polls opened, Madonna made a final get-out-the-vote grassroots effort in New York City’s Washington Square Park. During her surprise performance, the Clinton supporter, who has previously encouraged Democratic voters by appealing to their blue sense of humor, sang a 30-minute acoustic set for a couple hundred lucky fans. With a playlist heavy on well-known hits, the show quickly became a sing-along, with numbers including “Rebel Heart,†“Like a Prayer,†and John Lennon’s “Imagine.†According to Billboard, Madge also told her audience, “Vote with your heart, vote with your mind, vote with your spirit, vote with your soul. Save this country, please.†Watch bits of the performance below.